How to do API versioning for APIs having the Cloud Function backends.

[AbhishekgowdaSC]

We need to do API versioning for the API having the multiple Cloud Function backends. Since we are using multiple cloud functions we can not specify the version in base path in open api config . Need something like we need to send the api version number from the headers and validate, but not sure how exactly we can do it can some one help on this?

[qiwzhang]

You may need to use version prefix in your path. e.g. "/v1/path", "/v2/path". In your OpenAPI spec, you can specify the x-google-backend at operation level. Similar to this example.

Something like:

paths:
   /v1/path:
      get:
          x-google-backend:
              address: v1_backend_cloud_function

You may have to use path_translation to translate the path

[AbhishekgowdaSC]

The above solution will not work in our case. Can we send some default header values via this and validate the version?

[qiwzhang]

Are you suggesting using header to route to different version of your backend? Unfortunately, ESPv2 doesn't support routing to different backends based on HTTP header.

My impression is: GCLB supports routing based on HTTP headers. You can check it out.